Joseph G. Brand, III, 75, of Chester Springs, a research neuroscientist known mostly for his work with the sense of taste, died Dec. 28 of Parkinson’s disease at home.

Dr. Brand worked for nearly half a century as a researcher and associate director at Monell Chemical Senses Center in Philadelphia. Monell is a scientific institute for research on taste and smell, and much of Dr. Brand’s research focused on taste in humans and animals.

He became internationally known in 2005 for his research on cats, demonstrating that they had a genetic defect that prevented them from tasting sweets. It was an important conclusion that showed a connection between genes and behavior.

“He did real work,” said Gary Beauchamp, a faculty member and the former director and president at Monell. “He didn’t just direct others. He worked side-by-side with them, and the care with which he did that work and treated his colleagues was remarkable.”

Cat owners and scientists were intrigued by the finding, and Dr. Brand spent the rest of his life advising dubious cat owners about their pets’ diets. Many owners insisted that their cats could taste sweets because they liked ice cream and cake. No, Dr. Brand would tell them, it’s the fat in those treats the cats like.

“He got so many letters about that,” said his wife, Dr. Gail Corrado. “He couldn’t believe the impact that had on so many people.”

“Because cats can’t taste sweets, they’re cranky,” Dr. Brand joked in an article that was published in The Inquirer in 2005.

From the early 1970s until his retirement in 2010, Dr. Brand “used the techniques of biochemistry, biophysics, and molecular biology to explain chemosensory-directed behavior,” he wrote in a short biography. He said he was “asking a behavioral question and looking for a molecular answer.”

In addition to his research, Dr. Brand was an effective mentor and teacher, and former students told of how he inspired them to pursue their own scientific careers. “Dr. Brand is another rare renaissance scientist whose breadth of knowledge about the chemosensory world contributed to many careers and allied fields,” Monell said in a statement.

Born in 1945 in Lebanon, Pa., to Joseph and Bessie Brand, Dr. Brand grew up in Denver, Pa. He and his father fished and hunted, and he played the trumpet. Even in high school, he knew he wanted to study biochemistry.

Dr. Brand received a bachelor’s degree in chemistry from Trinity College, and a doctorate in biophysics at the University of Rochester. He met Bridget MacManus while in Rochester. They married and had a daughter, Megan, and a son, Andrew.

The family moved to Ardmore when Dr. Brand started working for the Monell Center. He published many scientific articles and taught as an adjunct professor at the Dental School of the University of Pennsylvania.

After divorcing, Dr. Brand connected with Corrado in 1983 through a dating service. They met at a Bennigan’s restaurant at the King of Prussia Mall, and she knew he was a keeper from the start. They talked science and chemistry, and the first word that came to her mind when she saw him was “Yes.”

They married in 1986, and her daughter from a previous marriage, Lisa, joined the family. They lived in Wayne for more than 25 years before moving to Chester Springs.

Dr. Brand liked the outdoors, and spent his free time tending to his yard and gardens. He was so frugal that neighbors bought him a plunger for Christmas one year because he had borrowed theirs so often. He was good at fixing things around the house, and he replaced all the windows on the third floor of Beauchamp’s house when he stayed there for a while.

He liked chocolate and puns, and disliked cold weather. The doctors loved dancing and parties, and “Wonderful Tonight” by Eric Clapton was their special song.

“I never met a person who didn’t like him,” Beauchamp said. “He was so honest, so helpful.”

In addition to his wife, children, stepdaughter, and ex-wife, Dr. Brand is survived by one grandson, and other relatives. A sister died earlier.

Donations in his name may be made to the Monell Summer Apprenticeship Program, 3500 Market St., Phila., Pa. 19104, or email Jen Trachtman at jtrachtman@monell.org.